Some of Britain's biggest lobbying firms are urging ministers to impose legal controls on their industry after the Government failed to include plans for a compulsory register of their members in the Queen's Speech.

Proposals for a statutory register of lobbyists were left out of the list of planned new laws, despite concerns about the "secret" influence wielded over Whitehall by businesses and special interest groups.

Campaigners for open government and lobbying groups themselves complained that the Government had lost interest in regulation despite a coalition agreement pledge to regulate lobbyists and a warning from David Cameron that lobbying was "the next big scandal waiting to happen". Lobbying groups insisted they continue to want a "universal" register.

Michael Burrell, chairman of the Association of Professional Political Consultants (APPC), which maintains a voluntary register, said: "We're now in limbo as to exactly what the future holds with no clear direction of travel." But Tamasin Cave of the campaign group Spinwatch said the Government had to tackle a "£2bn commercial influence industry [which] operates almost entirely behind closed doors". She added: "To politicians, lobbyists help them do their job – they effectively subsidise our system. To the public they corrupt it, because lobbying privileges the wealthy and well connected."

A Cabinet Office spokesman said: "Introducing a statutory register of lobbyists is a complex issue, and it is important we get it right. We are currently considering the way forward."